Do we know yet what the red crosses on the map are? I'm betting they are dwemer ruins. That one guy (Thanks, guy! or lady whatever) circled all the crosses and many were in the mountains, especially in The Reach, where the Rourken clan might have had strongholds and of course a few are also in the Velothi Mountains, which according to lore were heavily populated by the dwemer.

7: The video should begin playing surrounded by black boarders. In the URL change the /d3/1/358... to /d3/3/358... for HQ (1 is normal, 3 is HQ)
Now with chrome click the spanner -> Save page as -> Video.mp4